Many kinds of removable band-type couplings for pipes exist in the art. It is noted that throughout the specification and claims, the term “pipe” encompasses any kind of generally cylindrical object, and the terms “clamp” and “coupling” are used interchangeably.
For example, one well known type of pipe coupling includes a seal clamp housing. Clamp members are positioned face to face and a tightening element is tightened to press an annular seal element against the outside of the pipe inserted through the seal clamp housing. One end of the tightening element is generally installed in one of the clamp members and the other end must be brought into a socket or opening formed in the other clamp member.
The tightening elements are generally a row of bolts, each cooperating with a nut, which are tightened by a torque wrench and the like. The bolts fit into holes or other kinds of openings before tightening.
Examples of clamps used to repairs holes and longitudinal cracks in water and wastewater pipes are the EZ-MAX line of repair clamps and the VERSA-MAX line of clamps/couplings, both manufactured and distributed by KRAUSZ. VERSA-MAX is a repair coupling and clamp in a single device, capable of repairing holes and cracks and joining pipes with the same or different circumference.
Prior art repair clamps of this type typically have at least 4 tightening elements, that is, four bolts, which must be tightened to effect the seal.